JPH0587797A - Analyzing method of distribution of molecular weight of high-molecular weight polyacrylamide - Google Patents

Abstract

PURPOSE:To enable execution of an efficient and accurate analysis by a method wherein high-molecular weight polyacrylamide is dissolved by a phosphoric acid buffer and then the solution IS subjected to analysis by a gel permeation chromatograph (GPC) using the phosphoric acid buffer as a moving phase. CONSTITUTION:A phosphoric acid buffer of a moving phase is made to flow beforehand from a moving-phase storage tank 1 by a pump 2 and a steady state is prepared. Next, a sample dissolved by the phosphoric acid buffer is injected from a manual injector 3. This sample is sent to a column 4 by the moving phase of GPC and detected by a detector 6. Data thus obtained are processed for quantification computation by a data processing device 7. Herein the concentration of the phosphoric acid buffer must be the one which makes high-molecular weight polyacrylamide dissolved in such a degree as enabling reproduction of a chromatogram, and concretely, the concentration in a range of 200 to 400mM is preferable. Besides, it is desirable that the moving phase of the GPC is identical with a solution for dissolution in terms of the operation. As for the separation column to be used in the GPC, the one filled up with a general-purpose high-molecule gel can be used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for analyzing high molecular weight polyacrylamide having a weight average molecular weight of more than 10 million. More specifically, it relates to quality control and performance evaluation of high molecular weight polyacrylamide using gel permeation chromatograph (hereinafter referred to as GPC).

[0002]

2. Description of the Related Art Polyacrylamides, especially those having a high molecular weight exceeding 10 million in weight average molecular weight, are excellent in abrasion resistance, heat resistance and chemical resistance, and have been developed for various uses as high-performance materials.

Therefore, quality control, performance evaluation, etc. are required for use in such materials, and it is desired to analyze the molecular weight distribution of high molecular weight polyacrylamide. Therefore, conventionally, such polyacrylamide was dissolved in about 100 mM of sodium nitrate and potassium chloride, and the solution was analyzed by GPC using sodium nitrate, potassium chloride and the like as a mobile phase.

[0004]

However, in the conventional method, there is a problem that the chromatogram cannot be reproduced because the high molecular weight polyacrylamide has poor solubility in sodium nitrate and potassium chloride. Therefore, quality control and performance evaluation of high molecular weight polyacrylamide could not be performed accurately, and it was often the first time that it was found that the material had defects when it was made into a product.

Therefore, the present invention was found to find a new solvent for dissolving high molecular weight polyacrylamide,
It is an object of the present invention to solve the above problems all at once.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems, and as a result, have found that high molecular weight polyacrylamide dissolves very well in a phosphate buffer, and therefore, the present invention is made. I arrived.

That is, the present invention is characterized in that a high molecular weight polyacrylamide is dissolved in a phosphate buffer solution and then the solution is subjected to gel permeation chromatography using a phosphate buffer solution as a mobile phase for analysis. And

Here, the concentration of the phosphate buffer must be such that high molecular weight polyacrylamide can be dissolved to such an extent that the chromatogram can be reproduced.
The range of 200 mM-400 mM is preferable. If the content is less than this range, the solubility will decrease, and if it exceeds this range, the solubility will not change. P of phosphate buffer
H is not particularly limited, but is preferably in the weakly acidic range to the neutral range from the viewpoint of preventing column deterioration. The phosphate buffer solution itself may be a commercially available one or may be purified and used.

In order to dissolve the high molecular weight polyacrylamide in the phosphate buffer solution, for example, the high molecular weight polyacrylamide may be placed in a beaker and an appropriate amount of the phosphate buffer solution may be added thereto, but the method is not limited. .. The amount of the phosphate buffer required for the dissolution depends on the amount of the sample, but the dissolution rate at which the chromatogram can be reproduced is about 0.1% by weight.

When high molecular weight polyacrylamide is added to the phosphate buffer, the high molecular weight polyacrylamide dissolves and is subjected to GPC. A well-known sample introduction device can be used to attach to GPC.
Can be injected into a PC.

The solution injected into GPC is applied to a separation column using a phosphate buffer as a mobile phase. Where GPC
It is preferable for the operation of the apparatus that the mobile phase and the solution for dissolution are the same.

As the separation column used in GPC, a column packed with a general-purpose polymer gel can be used. For example, a packed column of vinyl alcohol copolymer can be mentioned as a suitable example.

As the GPC detecting means, for example, a differential refractive index detector is preferably used.

[0014]

According to the present invention, the solubility of high molecular weight polyacrylamide is improved, and thus the reproducibility of the chromatogram by GPC is improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus configuration for carrying out the method of the present invention will be described with reference to the drawings. FIG. 1 shows an example of an apparatus for carrying out the method of the present invention, 1 is a mobile phase reservoir, 2 is a liquid feed pump, 3 is a manual injector, 4 is a column, 5 is a column oven, and 6 is a differential refractive index detection. A container 7 is a data processing device.

In the analysis, the mobile phase is preliminarily flowed from the mobile phase storage tank 1 by the pump 2 to create a steady state.
Next, the sample is injected from the manual injector 3.
The injected sample is sent to the column 4 in the column oven 5 by the mobile phase and detected by the detector 6. This data is processed by the data processing device 7, and quantitative calculation is performed.

Using the above apparatus, analysis was conducted under the following analysis conditions. (1) Preparation of sample After dissolving high molecular weight polyacrylamide in 200 mM phosphate buffer, 200 μl of the solution is injected into GPC.

(2) Analytical conditions Column: Asahipak GS-710H (manufactured by Shimadzu Corporation) (7.6 mm ID × 250 mml) Mobile phase: 200 mM phosphate buffer Flow rate: 1.0 ml / min Temperature : 40 ° C. Detector: RID-6A (Differential Refractive Index Detector manufactured by Shimadzu Corporation) Sensitivity: 64 × 10 ⁻⁶ RIUFS Polarity: + (3) Analysis results The results of analysis under the above analysis conditions are shown in FIG. Show. From this figure, according to the present invention, high molecular weight polyacrylamide
You can see that you can analyze with high sensitivity. The vertical axis in FIG. 2 represents the signal intensity and the horizontal axis represents the holding time.

[0019]

According to the present invention, high molecular weight polyacrylamide can be analyzed efficiently and accurately. Further, the obtained molecular weight distribution has a special effect that quality control and performance evaluation of high molecular weight polyacrylamide can be easily performed.

[Brief description of drawings]

FIG. 1 shows an apparatus for implementing the arrangement of the invention.

FIG. 2 is a diagram showing the results of analysis by the method of the present invention.

[Explanation of symbols]

 1: Mobile phase storage tank 4: Analytical column 6: Detector

Claims (1)

[Claims] 1. A high-molecular-weight polymer characterized by dissolving a high-molecular-weight polyacrylamide in a phosphate buffer and then subjecting the solution to gel permeation chromatography using a phosphate buffer as a mobile phase for analysis. Molecular weight distribution analysis method for polyacrylamide.